Pneumatic sheet laying-off device



5 Sheets-Sheet 1 K. H. TOMTLUND PNEUMATIC SHEET LAYING-OFF DEVICE Filed Feb. 19, 1929 Dec. 29, 1931.

M w 2 W br we ea. 29, 1931. TOMTLUND 1,838,200

PNEUMATIC SHEET LAYING-OFF DEVICE Filed Feb. 19, 1929 5 Sheets-Sheet 2 In Veil/07" flirr/He/ye 7507/70/10 Hl/orne v.

Dec. 29, 1931. K. H. TOMTLUND 1,838,200

PNEUMATIC SHEET LAYING-OFF DEVICE Filed Feb. 19, 1929 5 Sheets-Sheet 3 bran/or /far///e /9e 75/21/7000 40 phere and are instead put in communication directed towards the valve 11 is a wear plate Patented Dec. 29, 1931 UNEFEE STATES PATENT FFECE KARLHELGE T OMT'LUND, OF KARLSTAD, SWEDEN PNEUMATIC SHEET LAYING-OFF DEVICE Application filed February 19, 1929, Serial No. 341,122, and in Sweden December 6, 1927.

The present invention relates to improvewards one end of the laying-oil drum. Fig. ments in pneumatic sheet laying-01f devices 2 shows the device viewed from the left in for paper machines or the like. Such de- Fig. 1. Figs. 3 and 4 show to a larger scale vices operate to catch and hold the' sheet or the laying-off drum viewed towards one end 5 sheets cut oii' from the paper web produced and in axial section, respectively. Fig. I 5 55 in the machine and to lay oil such sheet or is a diagrammatic and partly sectional view sheets at the desired place. The device may of a second embodiment. consist of a rotary roll or drum, and the Referring to the embodiment illustrated sheet catching and holding means may conin Figs. 1 to 4, inclusive, the laying-off desist of holes in the surface of the drum, and vice consists of a drum 1 having a hollow of means for alternately putting said holes interior which forms a suction or vacuum in communication with a vacuum or suction chamber 20. Said drum is journalled in bear conduit so as to catch and hold the sheets by gs 2 and mmunicates through its hollow suction through said holes, and with the outtrunnion 3 with a vacuum or suction conduit 15 side air so as to relieve the suction and re- 4. The shell of the drum 1 is provided along 65 leas th sh t two diametrically opposite generatrices with According to the present invention the two groups of holes 5 and 6. drum is provided with an interior chamber ch of these two groups of holes 5 and 6 which is in constant communication with the mm nicates with a passageway 7 and 8, re-

vacuum or suction conduit and is thus al- PeCtively,providedin the shell,said passageways under vacuum, and with one or more ays ing pen at one end of the drum. passageways which communicate with the id end Wal Of the drum 1 is provided holes or apertures in the shell of the drum, Wi h WO ports 9 and 10 located on the same which latter is also provided with a valve diameter as the passageways 7 and 8 but which is arranged in such manner that dur- 010861 to the aXis of the drum. Adjustably ing the rotation of the drum the passageway mounted on the hollow trunnion 3 adjacent or passageways are alternately put in comsaid end wall of the drum 1 is a distributing munication with said interior vacuum cham- "alve 11 having a sector-shaped cavity 12 her in the drum and with the atmosphere. directed towards the drum and adapted to By this arrangement the advantage is atput the passageway 7 in communication with tained that the vacuum is completely relieved the port 9, Or the passageway 8 in communionly in the passageways communicating with cation with the port 10. Said valve 11 also the holes or apertures in the shell of the drum, has a sector-shaped portion or plate 13 whereas the interior chamber. which has a d Y pp site he c v y 12 and comparatively large volume in relation to adapted to close the port 9, or 10, when durthe passageway or passageways forms a vacing the rotation of the drum 1 the passageuum reservoir. way 7 or 8, moves out of the cavity 12 and A di l h th passageways are thus obtains communication to the atmosshut oh? from communication with the atmosph r secured to the end. of the drum 1 with the interior chamber of the drum, the 14 of suitable metal, said plate having holes vacuum drop in the passageway or passage-V corresponding to the orifices of the passage wayswhich may have a length of several ways 7 and 8 and to the ports 9 and 10. The meters-becomes very small and the suction valve 11 is forced against the wear plate 14 required for catching and holding the sheet by two coil springs 15 interposed between to the drum is set up practically instantanethe valve 11 and the adjacentbearing 2 as ously. shown in Fig. 2.

n the accompanying drawings two embodi- The paper web 16 runs between the drum ments of the invention are illustrated; Fig. 1, which rotates in the direction indicated by 1 shows a sheet laying-0E device viewed tothe arrow in Fig. 3, and a roller 17 cooperating with the drum 1, after which the web runs in between the drum 1 and a roller 19 provided with a knife 18 which extends across the entire width of the paper web. Said roller 19 is geared to the drum 1 by gears 21, 22 in such manner that the roller 19 makes two revolutions for each revolution of the drum 1. and so that at each revolution of the roller 19 the knife 18 enters one of two grooves 23 and 24 provided diametrically opposite each other in the surface of the drum 1.

For each revolution of the roller 19 the knife 18 will thus out off a piece or sheet from the paper web of a length equal to one-half of the periphery of the drum 1. Before the sheet is cut off its forward edge, i. e. the forward edge of the paper web is caught and held to the surface of the drum 1 by suction, for instance through the holes 6, and the web will thus follow the drum 1 while the sheet is cut off and until the orifice of the passagewav 8 moves out .from under the valve 11 and comes in communication with the atmosphere, when the suction through the holes 6 held on to the surface of the drum 1, and

when during the rotation of the roller 19 the knife 18 again strikes the web, a second sheet is cut ofl which is soon afterwards laid off in the manner above described.

Instead of putting the holes 5 and 6 in communication with the atmosphere for the purpose of laying-off the sheet, said holes may be put in communication with .a compressed air supply in any suitable manner,

' for instance by providing the valve 11 with a chamber or cell connected to a compressed air conduit, so that when the passageway 7 or 8 comes in register with such cell, the sheet is blown off from the laying-off drum.

The embodiment illustrated in Fig. 5 differs from the embodiment above described mainly in that the l.ayingoff drum 1 does not form a portion of the cutting-01f device. According to this embodiment the knife 31 is attached to a rotatably journalled roller which is geared to the laying off drum 1 by means of a train of gears 32, 33, 34in such manner that said roller 30 makes two revolutions for each revolution of the drum 1. The knife 11 does not cooperate with the layingoff drum 1, however, as in the embodiment above described, but with a stationary knife 38. The roller 30 is geared by means of gears 35, 36 to two rollers 39 and 40 in such manner 7 that the roller 30 makes one revolution for each revolution of the roller 40. The roller 39 is provided with a circular knife 41 which enters an annular groove 42 in the circumference of the roller 40 and cuts the paper or pulp web 16 longitudinally.

The paper or pulp web 16 runs in between and is cut longitudinally between the rollers 39 and 40 and thence over a guide plate 43 and the stationary knife 38 and drops by gravity on to the laying-off drum 1 which runs in the direction indicated by the arrow. The forward edge of the paper web runs in between the laying-off drum 1 and a roller 44 bearing against said drum, and is attracted and held 'to the laying-off drum 1 when the passageway 7 connected to the holes 5 moves in under the valve plate 11. The laying-off drum 1 is geared to the roller 30 in such manner that the knife 31 passes the stationary knife 38 and cuts ofi the sheet only after the forward end of the latter has been attached to the drum 1 in the manner above described.

The sheet cut off is now brought along by the drum 1 until the passageway 7 moves out from under the valve plate 11, so that the suction in said passageway is relieved and the forward end of the sheet is released from the laying-off drum. Shortly before this happens the rear edge of the sheet haspassed the roller 44 and is thus free, so that when the forward end-of the sheet is released from the laying-off drum 1, the sheet will drop on to the desired place on the table 25. In the two embodiments above described the forward edge of the paper web is thus held to the laying-off drum before the sheet is cut off, and the sheet is also held during a certain portion of the revolution of the laying-off drum, so that the sheet'will be laid off at' the desired place, and all sheets will form an even pile, as shown in Figs. 3 and 5.

The invention is, of course, not limited to the embodiments above described and illustrated in the drawings the details of which may be modified in several respects without departing from the principle of the invention.

I claim:

1. In a sheet laying-off device for paper machines and the like, the combination of a rotary drum, the interior of said drum constituting a vacuum chamber, said drum having at least one passageway opening in one end surface of the drum and communicating with holes opening in the circumferential surface of said drum, said drum having at least one port in its said end surface leading to said interior vacuum chamber, and

a valve bearing against said end surface of said drum, said valve being adapted during a portion of a revolution of said drum to effect communication between said port and said passageway and during another portion of a revolution of said drum to close said port and open said opening of said passageway to the outside air.

2. In a sheet laying-off device for paper machines and the like, the combination of a rotary drum, the interior of said drum constituting a vacuum chamber, said drum having at least one passageway opening in one end surface of said drum and communicating with holes opening in the circumferential surface of said drum, said drum having at least one port in its said end surface leading to said interior vacuum chamber, and a valve bearing against said end surface of said drum, said valve having a cavity adapted during a portion of a revolution of said drum to effect communication between said port and said passageway.

3. In a sheet laying-off device for paper machines and the like, the combination of a rotary drum, the interior of said drum constituting avacuum chamber, said drum having at least one passageway opening in one end surface of said drum and communicating with holes opening in the circumferential surface of said drum, said drum having at least one port in its said end surface leading to said interior vacuum chamber, and a valve bearing against said end surface of said drum, said valve having a cavity adapted during a portion of a revolution of said drum to effect communication between said port and said passageway, and said valve having a plate adapted to cover said port during the remaining portion of a revolution of said drum.

4. In a sheet laying-off device for paper machines and the like, the combination of a rotary drum, the interior of said drum constituting a vacuum chamber, said drum having a number of passageways equally spaced circumferentially and communicating with holes opening in the circumferential surface of said drum, said passageways opening in one end surface of said drum, a corresponding number of ports in said end surface of said drum leading to said interior vacuum chamber, and a valve bearing against said end surface of said drum, said valve having a cavity adapted during a portion of a revolution of said drum to establish connection between said passageways and their corresponding ports, and said valve having a plate adapted to cover such ports as are not in communication with said cavity.

5. In a sheet laying-off device for paper machines and the like, the combination of a rotary drum, the interior of said drum constituting a vacuum chamber, said drum having a number of passageways equally spaced circumferentially and communicating with holes opening in the circumferential surface of said drum, said passageways opening in one end surface of said drum, a corresponding number of ports in said end surface of said drum leading to said interior vacuum chamber, said ports being located substanside air.

KARL HELGE TOMTLUND. 

